Thanks for the info. I wanted to know the dimensions beforehand so I wouldn't have to open the camera and leave it open till I cut the glass.

3mm+1mm sound a lot more than what I thought it was going to be though.

I may be wrong here, but since the filter has a refractive index greater than the air, removing it should be equivalent to moving the lens away from the sensor (disabling infinity focus), and replacing it with a thicker glass should affect the minimum focus distance (no big deal), so I guess I'll go for a 4mm+ replacement.

Did autofocus continue to work with your GX1 after removing the filters? I am not 100% sure about this, but since it relies on visible signal from the sensor for autofocus, unless it also uses distance info from the lens (like the Nikons do), converting it to a full spectrum camera shouldn't affect it.

Hi

I have 4 hot mirrors and dust filters in front of me, GF1 and GH2

The panasonic dust filters are IR cutting, I checked. you need to take them out. The olympus ones are not IR cutting from what I have read

The dimensions are 22.24mm x 17.24mm and 3mm (thickness doesn't matter as much as you are adding an equivalent refractive layer if you are doing a DIY infrared conversion)

The problem isn't autofocus not working, the question is focal range. You may find without a replacement filter that when in the IR range you may find infinity is a couple of feet or less!

I used a 2mm spectrosil window and tightened the adjustment screws on the sensor holder, true infinity focus works at all spectral ranges from 350nm to 920nm. I bought mine custom cut from an optical glass company, it was cheaper (and better optical performance) than buying a ready made filter

For info, if you buy a decent uv/ir cut filter then I found you could achieve infinity focus without an internal filter for normal visible light